Updated at 12:21 a.m. ET
California Sen. Kamala Harris swung at Joe Biden for working with segregationists and opposing busing legislation. She told the former vice president how she helped integrate her California school as Biden struggled to respond, zeroing in on President Trump throughout the night instead. Vermont Sen. Bernie Sanders admitted "Medicare-for-all" would raise middle-class taxes but said it would lower health care costs. South Bend, Ind., Mayor Pete Buttigieg invoked his faith as one reason Republicans are wrong on family separations at the U.S.-Mexico border. And all the candidates said their health care proposals would give care to undocumented immigrants.
7 Highlights, In Video
Harris, the only black candidate onstage, went after Biden on his civil rights record while telling her own personal story.
WATCH: Harris says she doesn't think Biden is a racist, but she talks directly to Biden about his having worked with segregationists on the issue of school busing. #DemDebate2 pic.twitter.com/Ytb2xvOhux— NBC News (@NBCNews) June 28, 2019
Biden responded and said Harris mischaracterized his record.
"There are moments in history where states fail to preserve the civil rights of all people"— NBC News (@NBCNews) June 28, 2019
WATCH: Biden and Harris tense exchange during #DemDebate2 https://t.co/2vxLWBKssH pic.twitter.com/aLMeT5pdMA
As the crowded debate stage got too unwieldy, Harris said America doesn't want a "food fight."
Buttigieg argued that Republicans who invoke their faith are being hypocritical when it comes to the crisis at the border.
Sanders defended his democratic socialist beliefs.
Savannah Guthrie: "What is your response to those who say nominating a socialist would re-elect Donald Trump?"— MSNBC (@MSNBC) June 28, 2019
Bernie Sanders: "Well I think the response is ... the last poll I saw had us 10 points ahead of Donald Trump." pic.twitter.com/kgEzTL1ysy
And California Rep. Eric Swalwell tried to get in a dig at Biden's age.